 /*******************************************************************************
  * Copyright (c) 2000, 2007 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  * IBM Corporation - initial API and implementation
  *******************************************************************************/
 package org.eclipse.ui.internal.texteditor;

 import org.eclipse.swt.SWT;
 import org.eclipse.swt.custom.StyledText;
 import org.eclipse.swt.events.DisposeEvent;
 import org.eclipse.swt.events.DisposeListener;
 import org.eclipse.swt.events.FocusListener;
 import org.eclipse.swt.events.KeyEvent;
 import org.eclipse.swt.events.KeyListener;
 import org.eclipse.swt.graphics.Color;
 import org.eclipse.swt.graphics.Font;
 import org.eclipse.swt.graphics.FontData;
 import org.eclipse.swt.graphics.GC;
 import org.eclipse.swt.graphics.Point;
 import org.eclipse.swt.layout.GridData;
 import org.eclipse.swt.layout.GridLayout;
 import org.eclipse.swt.widgets.Composite;
 import org.eclipse.swt.widgets.Display;
 import org.eclipse.swt.widgets.Label;
 import org.eclipse.swt.widgets.Shell;

 import org.eclipse.jface.resource.JFaceResources;

 import org.eclipse.jface.text.BadLocationException;
 import org.eclipse.jface.text.Document;
 import org.eclipse.jface.text.IDocument;
 import org.eclipse.jface.text.IInformationControl;
 import org.eclipse.jface.text.IInformationControlExtension;
 import org.eclipse.jface.text.IRegion;
 import org.eclipse.jface.text.source.SourceViewer;

 import org.eclipse.ui.editors.text.TextSourceViewerConfiguration;

 import org.eclipse.ui.internal.editors.text.EditorsPlugin;

 /**
  * Source viewer based implementation of <code>IInformationControl</code>.
  * Displays information in a source viewer configured with the text editor
  * preference store.
  *
  * @since 3.0
  */
 class SourceViewerInformationControl implements IInformationControl, IInformationControlExtension, DisposeListener {

     /** Border thickness in pixels. */
     private static final int BORDER= 1;


     /** The control's shell */
     private Shell fShell;
     /** The control's text widget */
     private StyledText fText;
     /** The control's source viewer */
     private SourceViewer fViewer;
     /** The optional status field. */
     private Label fStatusField;
     /** The separator for the optional status field. */
     private Label fSeparator;
     /** The font of the optional status text label.*/
     private Font fStatusTextFont;
     /** The maximal widget width. */
     private int fMaxWidth;
     /** The maximal widget height. */
     private int fMaxHeight;
     /** The horizontal scroll index. */
     private int fHorizontalScrollPixel;

     /**
      * Creates a source viewer information control with the given shell as
      * parent and the given font.
      *
      * @param parent the parent shell
      * @param symbolicFontName the symbolic font name
      */
     public SourceViewerInformationControl(Shell parent, String symbolicFontName) {
         this(parent, SWT.NO_TRIM | SWT.TOOL, SWT.NONE, symbolicFontName, null);
     }

     /**
      * Creates a source viewer information control with the given shell as
      * parent. The given shell styles are applied to the created shell. The
      * given styles are applied to the created styled text widget. The text
      * widget will be initialized with the given font. The status field will
      * contain the given text or be hidden.
      *
      * @param parent the parent shell
      * @param shellStyle the additional styles for the shell
      * @param style the additional styles for the styled text widget
      * @param symbolicFontName the symbolic font name
      * @param statusFieldText the text to be used in the optional status field
      * or <code>null</code> if the status field should be hidden
      */
     public SourceViewerInformationControl(Shell parent, int shellStyle, int style, String symbolicFontName, String statusFieldText) {
         GridLayout layout;
         GridData gd;

         fShell= new Shell(parent, SWT.NO_FOCUS | SWT.ON_TOP | shellStyle);
         Display display= fShell.getDisplay();
         fShell.setBackground(display.getSystemColor(SWT.COLOR_BLACK));

         Composite composite= fShell;
         layout= new GridLayout(1, false);
         int border= ((shellStyle & SWT.NO_TRIM) == 0) ? 0 : BORDER;
         layout.marginHeight= border;
         layout.marginWidth= border;
         composite.setLayout(layout);
         gd= new GridData(GridData.FILL_HORIZONTAL);
         composite.setLayoutData(gd);

         if (statusFieldText != null) {
             composite= new Composite(composite, SWT.NONE);
             layout= new GridLayout(1, false);
             layout.marginHeight= 0;
             layout.marginWidth= 0;
             composite.setLayout(layout);
             gd= new GridData(GridData.FILL_BOTH);
             composite.setLayoutData(gd);
             composite.setForeground(display.getSystemColor(SWT.COLOR_INFO_FOREGROUND));
             composite.setBackground(display.getSystemColor(SWT.COLOR_INFO_BACKGROUND));
         }

         // Source viewer
 fViewer= new SourceViewer(composite, null, style);
         fViewer.configure(new TextSourceViewerConfiguration(EditorsPlugin.getDefault().getPreferenceStore()));
         fViewer.setEditable(false);

         fText= fViewer.getTextWidget();
         gd= new GridData(GridData.BEGINNING | GridData.FILL_BOTH);
         fText.setLayoutData(gd);
         fText.setForeground(parent.getDisplay().getSystemColor(SWT.COLOR_INFO_FOREGROUND));
         fText.setBackground(parent.getDisplay().getSystemColor(SWT.COLOR_INFO_BACKGROUND));
         fText.setFont(JFaceResources.getFont(symbolicFontName));

         fText.addKeyListener(new KeyListener() {

             public void keyPressed(KeyEvent e) {
                 if (e.character == 0x1B) // ESC
 fShell.dispose();
             }

             public void keyReleased(KeyEvent e) {}
         });

         // Status field
 if (statusFieldText != null) {

             // Horizontal separator line
 fSeparator= new Label(composite, SWT.SEPARATOR | SWT.HORIZONTAL | SWT.LINE_DOT);
             fSeparator.setLayoutData(new GridData(GridData.FILL_HORIZONTAL));

             // Status field label
 fStatusField= new Label(composite, SWT.RIGHT);
             fStatusField.setText(statusFieldText);
             Font font= fStatusField.getFont();
             FontData[] fontDatas= font.getFontData();
             for (int i= 0; i < fontDatas.length; i++)
                 fontDatas[i].setHeight(fontDatas[i].getHeight() * 9 / 10);
             fStatusTextFont= new Font(fStatusField.getDisplay(), fontDatas);
             fStatusField.setFont(fStatusTextFont);
             GridData gd2= new GridData(GridData.FILL_VERTICAL | GridData.FILL_HORIZONTAL | GridData.HORIZONTAL_ALIGN_BEGINNING | GridData.VERTICAL_ALIGN_BEGINNING);
             fStatusField.setLayoutData(gd2);

             // Regarding the color see bug 41128
 fStatusField.setForeground(display.getSystemColor(SWT.COLOR_WIDGET_DARK_SHADOW));

             fStatusField.setBackground(display.getSystemColor(SWT.COLOR_INFO_BACKGROUND));
         }

         addDisposeListener(this);
     }

     /*
      * @see org.eclipse.jface.text.IInformationControlExtension2#setInput(java.lang.Object)
      */
     public void setInput(Object input) {
         if (input instanceof String )
             setInformation((String )input);
         else
             setInformation(null);
     }

     /*
      * @see IInformationControl#setInformation(String)
      */
     public void setInformation(String content) {
         if (content == null) {
             fViewer.setInput(null);
             return;
         }

         IDocument doc= new Document(content);
         fViewer.setInput(doc);
         
         // ensure that we can scroll enough
 ensureScrollable();

         fViewer.getTextWidget().setHorizontalPixel(fHorizontalScrollPixel);
     }

     /*
      * @see IInformationControl#setVisible(boolean)
      */
     public void setVisible(boolean visible) {
             fShell.setVisible(visible);
     }

     /*
      * @see org.eclipse.swt.events.DisposeListener#widgetDisposed(org.eclipse.swt.events.DisposeEvent)
      */
     public void widgetDisposed(DisposeEvent event) {
         if (fStatusTextFont != null && !fStatusTextFont.isDisposed())
             fStatusTextFont.dispose();

         fStatusTextFont= null;
         fShell= null;
         fText= null;
     }

     /*
      * @see org.eclipse.jface.text.IInformationControl#dispose()
      */
     public final void dispose() {
         if (fShell != null && !fShell.isDisposed())
             fShell.dispose();
         else
             widgetDisposed(null);
     }

     /*
      * @see IInformationControl#setSize(int, int)
      */
     public void setSize(int width, int height) {

         if (fStatusField != null) {
             GridData gd= (GridData)fViewer.getTextWidget().getLayoutData();
             Point statusSize= fStatusField.computeSize(SWT.DEFAULT, SWT.DEFAULT, true);
             Point separatorSize= fSeparator.computeSize(SWT.DEFAULT, SWT.DEFAULT, true);
             gd.heightHint= height - statusSize.y - separatorSize.y;
         }
         fShell.setSize(width, height);

         if (fStatusField != null)
             fShell.pack(true);
     }

     /*
      * @see IInformationControl#setLocation(Point)
      */
     public void setLocation(Point location) {
         fShell.setLocation(location);
     }

     /*
      * @see IInformationControl#setSizeConstraints(int, int)
      */
     public void setSizeConstraints(int maxWidth, int maxHeight) {
         fMaxWidth= maxWidth;
         fMaxHeight= maxHeight;
     }

     /*
      * @see IInformationControl#computeSizeHint()
      */
     public Point computeSizeHint() {
         Point size= fShell.computeSize(SWT.DEFAULT, SWT.DEFAULT);
         size.x= Math.min(size.x, fMaxWidth);
         size.y= Math.min(size.y, fMaxHeight);
         return size;
     }

     /*
      * @see IInformationControl#addDisposeListener(DisposeListener)
      */
     public void addDisposeListener(DisposeListener listener) {
         fShell.addDisposeListener(listener);
     }

     /*
      * @see IInformationControl#removeDisposeListener(DisposeListener)
      */
     public void removeDisposeListener(DisposeListener listener) {
         fShell.removeDisposeListener(listener);
     }

     /*
      * @see IInformationControl#setForegroundColor(Color)
      */
     public void setForegroundColor(Color foreground) {
         fText.setForeground(foreground);
     }

     /*
      * @see IInformationControl#setBackgroundColor(Color)
      */
     public void setBackgroundColor(Color background) {
         fText.setBackground(background);
     }

     /*
      * @see IInformationControl#isFocusControl()
      */
     public boolean isFocusControl() {
         return fText.isFocusControl();
     }

     /*
      * @see IInformationControl#setFocus()
      */
     public void setFocus() {
         fShell.forceFocus();
         fText.setFocus();
     }

     /*
      * @see IInformationControl#addFocusListener(FocusListener)
      */
     public void addFocusListener(FocusListener listener) {
         fText.addFocusListener(listener);
     }

     /*
      * @see IInformationControl#removeFocusListener(FocusListener)
      */
     public void removeFocusListener(FocusListener listener) {
         fText.removeFocusListener(listener);
     }

     /*
      * @see IInformationControlExtension#hasContents()
      */
     public boolean hasContents() {
         return fText.getCharCount() > 0;
     }

     /**
      * @param scrollIndex the new horizontal scroll index.
      */
     void setHorizontalScrollPixel(int scrollIndex) {
         scrollIndex= Math.max(0, scrollIndex);
         fHorizontalScrollPixel= scrollIndex;
     }
     
     /**
      * Ensures that the control can be scrolled at least to
      * <code>fHorizontalScrollPixel</code> and adjusts <code>fMaxWidth</code>
      * accordingly.
      *
      * @since 3.3
      */
     private void ensureScrollable() {
         IDocument doc= fViewer.getDocument();
         if (doc == null)
             return;

         StyledText widget= fViewer.getTextWidget();
         if (widget == null || widget.isDisposed())
             return;

         int last= doc.getNumberOfLines() - 1;
         GC gc= new GC(widget);
         gc.setFont(widget.getFont());
         int maxWidth= 0;
         String content= new String ();

         try {
             for (int i= 0; i <= last; i++) {
                 IRegion line;
                 line= doc.getLineInformation(i);
                 content= doc.get(line.getOffset(), line.getLength());
                 int width= gc.textExtent(content).x;
                 if (width > maxWidth) {
                     maxWidth= width;
                 }
             }
         } catch (BadLocationException e) {
             return;
         } finally {
             gc.dispose();
         }

         // limit the size of the window to the maximum width minus scrolling,
 // but never more than the configured max size (viewport size).
 fMaxWidth= Math.max(0, Math.min(fMaxWidth, maxWidth - fHorizontalScrollPixel + 8));
     }
     
 }

